The most immediate driver for FCoE is the imperative to deal with the cabling and card challenges with server racks and blades. With hundreds of servers in a rack supporting up to 1,000 virtual machines, the traditional way of connecting to these servers with individual FC cards and NICs is unsustainable. Converged network adapters (CNAs) reduce the number of cables in the rack by about two-thirds. Two 20Gb cables from the CNAs connect each server to a top-of-rack (ToR) switch. This ToR switch then connects to the existing Ethernet and FC networks.
The benefits of this approach will be lower cost blades and server racks that are easier to maintain, have lower heat, space, and power requirements, and will be more reliable. The biggest single saving (~$100,000 per rack) comes from reducing costs associated with cables and cabling.
Action Item: CIOs and senior managers in installations with significant FC infrastructure should focus on position the infrastructure to take advantage of lower cost and lower power servers and blades that will be available in volume in 2010 from the server vendors. The immediate task is to test that these server configurations will connect from the ToR switch to the existing FC and Ethernet networks, and to revise the operational and trouble-shooting procedures for FC cards and NICs to accommodate CNAs.
Footnotes: Emulex FCoE Calculator